Gel Permeation Chromatography-multiangle Laser Light Scattering Research Articles

The structure and dynamics of bottlebrushes: Simulation and experimental studies combined

Bottlebrushes are complex macromolecular structures composed of polymer chains densely tethered to another polymer chain via a stable covalent bond linkage. Although numerous experimental techniques have been successfully applied for the characterization of bottlebrush polymers, some parameters still cannot be determined. Herein new simulation method using a dedicated machine was used to confront its applicability for complex macromolecules simulations. The bottlebrushes were synthesized by atom transfer radical polymerization (ATRP) with varied degree of polymerization (N) of the side chains, poly(methyl methacrylate) (PMMA). Poly(2-(2-bromoisobutyryloxy)ethyl methacrylate) (PBiBEM) was used as macroinitiator with a degree of polymerization Nbb = 102. Degree of polymerization of side chains (Nsc) changed from 28 to 113. The bottlebrushes were characterized by Gel Permeation Chromatography – Multiangle Laser Light Scattering (GPC-MALLS), Pulsed-field Gradient Spin Echo Nuclear Magnetic Resonance (PGSE NMR), and combined Static and Dynamic Light Scattering methods (SLS-DLS). A novel calculation strategy via the Monte Carlo-class Dynamic Lattice Liquid (DLL) algorithm executed on a dedicated machine ARUZ was applied for theoretical studies. The experimental values concerning the scaling behavior of polymer size and dynamics were compared and confronted with simulation results.

Improved bioactivity and composition of Cordyceps militaris cultured with Panax ginseng

Abstract Cordyceps militaris is a commonly used edible and medicinal fungus in East Asia. Preparation of the mycelium and fermentation liquid by submerged fermentation using additives such as Panax ginseng for skin whitening applications has attracted wide attention. In the present study, we screened traditional Chinese medicines as additives to the liquid fermentation medium for C. militaris and performed systematical research on the changes of bioactivity and ginsenoside levels during the fermentation process. Total polysaccharide contents, cordycepin content, and polysaccharide molecular weight in the fermentation products were measured by UV spectrophotometry, high-performance liquid chromatography-diode array detection (HPLC/DAD), and gel permeation chromatography-multi angle laser light scattering (GPC-MALLS), respectively. In addition, the ginsenosides Rb1, Re, Rd, Rg1, and pseudoginsenoside F11 in the fermentation products were quantitatively analyzed by ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS). Panax ginseng significantly increased the cordycepin and total sugar contents, and the average molecular weight of polysaccharides in the fermentation liquid and the mycelium of C. militaris. At the same time, C. militaris enhanced the production of ginsenoside pseudoginsenoside F11, which is a unique component of Panax quinquefolium. The research provides scientific evidence for the application of C. militaris and P. ginseng as raw materials for food and medicines.

Green recovery of Se-rich protein and antioxidant peptides from Cardamine Violifolia: Composition and bioactivity

Cardamine violifolia (CV) is an important raw material for selenoprotein production. In this study, the protein of CV was extracted using conventional extraction (CE), ultrasound assisted extraction (UAE), pulsed electric pretreatment followed by CE (PEF + CE), and pulsed electric pretreatment followed by UAE (PEF + UAE), respectively. The result indicated that the yields of protein varied with extraction temperatures from 30 to 70 °C, while the highest yield was obtained at 40 °C for all these four methods. UAE showed the most effective extraction with a higher purity of protein powder (77%) and total selenium content (9097.33 ± 35.66 mg/kg). By application of response surface methodology, the protein yield was enhanced to 57.35 ± 0.92% at ultrasonic duration of 27 min, extraction temperature of 37 °C, and ultrasonic energy density of 8.125 W/mL. The obtained protein was further hydrolyzed by alcalase (37 °C, pH 10 for 5 h) and separated through ultrafiltration and size exclusion chromatography. Due to gel permeation chromatography-multi angle laser light scattering (GPC-MALLS) analysis, it was found that the CV protein hydrolysates were rich in dipeptides and tripeptides indicating promising antioxidant activities. Therefore, this study will contribute to the fabrication of selenium-rich proteins and antioxidant peptides as functional food ingredients.

Ultrasonic degradation of Persian gum and gum tragacanth: Effect on chain conformation and molecular properties

The present study introduces the ultrasonic modification of two Iranian native gum exudates, Persian gum (PG) and gum tragacanth (GT) for the first time. They were sonicated at a constant frequency of 20 kHz and temperature of 60 °C for various times (0, 2, 5, 10, 20, 30 and 40 min) and the changes in their molecular properties were investigated using oven drying, gel permeation chromatography-multiangle laser-light scattering (GPC-MALLS), rheometery and FTIR analysis. Results indicated that the soluble dry mass of both hydrocolloids was extensively enhanced (from less than 10% at time zero to more than 90% at the end of treatment time) by sonication. Moreover, the molecular weight and viscosity of gums dispersions were decreased with the increase of the treatment time. Fracture in polysaccharide chains was confirmed by analysis of the molecular weight parameters. Calculation of chain breaks and polydispersity index (PDI) revealed that scissions occurred at the backbone as well as the side branches. PG, owing to its higher molecular weight, displayed more extensive and faster degradation than GT. However, the chain rupture of GT was twice more than that of PG at the end of sonication time. The specific volume for gyration (SVg) and molecular density (ρ) showed that intact PG contains compactly packed molecules with greater number of cross-linked bonds compared to GT. Furthermore, the conformational changes into semi-flexible chains and worm-like coils were determined for both gums after 40 min sonication. Variation of the molecular density along with the results of FTIR analysis demonstrated that ultrasonication broke C–O–C bonds in both PG and GT leading to more flexible chains.

Preparation and characterization of epoxy-crosslinked soy protein adhesive

In this study, the soy protein was degraded and cross-linked with trimethylolpropane triglycidyl ether (THPTG) at 80 °C to prepare wood adhesive for interior plywood. Namely, by adding sodium hydroxide (NaOH), functional groups (-NH2, -COOH, and -OH) in soy protein were exposed and then reacted with epoxy groups to form a crosslinked water-resistance soy-protein adhesive under alkali condition. The optimum formulation of this adhesive was investigated. The molecular weights, chemical structure, bonding properties and water-resistance were characterized by gel permeation chromatography-multi-angle laser light scattering (GPC-MALLS), Fourier transform infrared spectroscopy (FTIR), plywood bonding test and three-cycle soak test. Results showed that at 2% NaOH, the molecular weight of soy protein isolate degradation (DSP) presented as 3.473e + 04 g·mol−1 was homogeneous and resulted in greater increase of amide II and amide III. The cross-linking reaction between THPTG and DSP resulted in the increase of both viscosity and sensitivity of infrared absorption peaks of –O–H (3100 cm−1) and C-N (1190 cm−1). Also, the adhesives synthesized from the SPI denatured with 2% NaOH and 9% THPTG did meet the wet strength for interior-use plywood panels (≥0.7 MPa) according to the China Industry Standard GB/T 9846.3-2004 and water resistance according to American National Standard for Hardwood and Decorative Plywood/Hardwood Plywood and Veneer Association.

Preparation and emulsifying properties of trace elements fortified gum arabic

Gum arabic was enriched with trace elements (Zn2+, Fe3+, Fe2+) by ion exchange against ZnCl2, FeCl3 and FeCl2. Trace elements content, molecular parameters and emulsifying properties of the gum arabic rich in trace elements (GARTE) were characterized by flame atomic absorption spectrometry (FAAS), gel permeation chromatography-multi angle laser light scattering (GPC-MALLS), interfacial rheometer, laser particle analyzer and zeta potentiometry. With trace elements, molecular weight and arabinogalactan protein (AGP) content of gum arabic have increased probably due to the high surface energy leading to the aggregation of protein. GARTE has good emulsion stability performance with increasing molecular weight and AGP content compared to the control gum arabic. GARTE can be applied as a natural functional ingredient for trace element fortification, where the ferric ions and zinc ions are chelated by the self-assembled polymer host.

Local β-glucan source from oyster mushroom (Pleurotus flabellatus) as potential usage in medical applications

Event Abstract Back to Event Local β-glucan source from oyster mushroom (Pleurotus flabellatus) as potential usage in medical applications Shaiful A. Mohamad1*, Nur Hafizati Abd Halim1, Choong Yew Keong2, Ahmad Zainuri Mohd Dzomir1, Hafizal Yazid1, Mohd Yusof Hamzah1 and Everina Nuri1 1 Malaysian Nuclear Agency, Malaysia 2 Herbal Medicine Research Centre, Institute for Medical Research, Ministry of Health (Malaysia), Malaysia Background Many applications of mushroom polysaccharides have been reported such as in drug delivery system, skin applications and as immunomodulatory agents. The polysaccharides can be obtained from the fruit body, mycelium, culture broth and spores of mushroom. In this study, oyster mushroom (Pleurotus flabellatus) culture was produced by submerged culture fermentation due to its higher productivity and faster fermentation rate. Methods The biomass obtained from submerged culture fermentation was extracted by using hot water extraction. The polysaccharides were tested using β-glucan kit and also studied using small angle X-ray scattering (SAXS) equipment. Then the polysaccharides were separated using column chromatography before determining the molecular weight using gel permeation chromatography-multi angle laser light scattering (GPC-MALLS). Results Both endopolysaccharide and exopolysaccharide obtained have shown the presence of β-glucan (1,3;1,6). The polysaccharides also showed the presence of high molecular weight (~3×10^6 Da) and low molecular weight components. SAXS results showed that the maximum agglomerate size was ~27 nm and the average size of globular was 2.6 nm. Conclusion The presence of high molecular weight β-glucan showed potential application as immunomodulatory agents. The polysaccharides can be classified as nanobiomaterials. These studies supported potential usage of local compounds in medical applications. Keywords: Pleurotus flabellatus, Immunomodulation, Small angle X ray scattering, β-Glucan, Submerged fermentation Conference: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”, Putrajaya, Malaysia, 3 Dec - 5 Feb, 2019. Presentation Type: Poster Presentation Topic: Miscellaneous Citation: Mohamad SA, Abd Halim N, Keong C, Mohd Dzomir A, Yazid H, Hamzah M and Nuri E (2019). Local β-glucan source from oyster mushroom (Pleurotus flabellatus) as potential usage in medical applications. Front. Pharmacol. Conference Abstract: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”. doi: 10.3389/conf.fphar.2018.63.00112 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 12 Oct 2018; Published Online: 17 Jan 2019. * Correspondence: Dr. Shaiful A Mohamad, Malaysian Nuclear Agency, Kuala Lumpur, Malaysia, shaifulazuar@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Shaiful A Mohamad Nur Hafizati Abd Halim Choong Yew Keong Ahmad Zainuri Mohd Dzomir Hafizal Yazid Mohd Yusof Hamzah Everina Nuri Google Shaiful A Mohamad Nur Hafizati Abd Halim Choong Yew Keong Ahmad Zainuri Mohd Dzomir Hafizal Yazid Mohd Yusof Hamzah Everina Nuri Google Scholar Shaiful A Mohamad Nur Hafizati Abd Halim Choong Yew Keong Ahmad Zainuri Mohd Dzomir Hafizal Yazid Mohd Yusof Hamzah Everina Nuri PubMed Shaiful A Mohamad Nur Hafizati Abd Halim Choong Yew Keong Ahmad Zainuri Mohd Dzomir Hafizal Yazid Mohd Yusof Hamzah Everina Nuri Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Changes in Turbidity, Zeta Potential and Precipitation Yield Induced by Persian Gum-Whey Protein Isolate Interactions During Acidification

To measure the molecular parameters of Persian gum (PG) (gathered from Kazeroon plains/Iran) by gel permeation chromatography-multiangle laser light scattering (GPC-MALLS), water-insoluble part of gum was removed using filtration method. In the following, acidification of whey protein isolate/PG mixture solutions (pH ∼ 7.00–2.00) at different biopolymer mixing ratio (r = 0.1–10) was induced by HCl, allowing turbidity, zeta potential and precipitation yield determinations. Contrary to previous studies, it was demonstrated that more than 93% of gum is composed of large water-insoluble particles and water-soluble part contains heavy and heterogeneous compounds with high weight-average molecular mass (up to 5.11 × 106 g/mol) and high dispersity index (∼2.54–6.64). Acid titration of the mixtures displayed that the net neutrality shifts to the higher pHs by increasing the mixing ratio, and the charge neutralization occurs at pHs near pHopt as well. Generally, the maximum interaction was found for a 1:1 WPI/PG mixture with the highest liquid precipitate yield achieved at pH 3.4. Practical Application Persian gum exudes from the wild almond tree (Amygdalus scoparia), growing in the Middle East countries. The characteristics of this hydrocolloid highly depend on the color of exudate and region of the tree. As a mixture with gum Arabic, it has wide industrial and pharmaceutical applications due to economic reasons and high functionality. However, very few scientific information about this gum has been already published. Some researchers have displayed the emulsifier, stabilizer and fat replacer ability of this gum. The interaction of PG with other biopolymers such as proteins would be beneficial in food and pharmaceutical applications in the form of gels, microcapsules, etc. In this study, we have measured the water-soluble and insoluble fractions and molecular parameters of PG gathered from Kazeroon plains. To have a basic knowledge for our future investigations on encapsulation ability of PG-WPI complexes, titration method was applied for different PG-WPI admixtures.

Structural Changes to Aspen Wood Lignin during Autohydrolysis Pretreatment

Aspen wood was subjected to autohydrolysis as a pre-treatment to characterize the structural changes occurring in lignin fractions during the pre-treatment process. Milled wood lignin (MWL) was isolated from both the native aspen wood and hydrolyzed wood chips, and its structural features were characterized by Fourier transform infrared (FT-IR), quantitative 13C, two-dimensional heteronuclear single quantum coherence (2D HSQC), and 31P nuclear magnetic resonance (NMR) spectroscopies, gel permeation chromatography/multi-angle laser light scattering (GPC-MALLS), and thermal analysis. The lignin remaining in the hydrolyzed wood chips revealed more phenolic OH groups, fewer aliphatic OH groups, higher syringyl/guaiacyl ratios (S/G), higher molecular weights, and narrower polydispersities than the native lignin of aspen wood. The inter-unit linkages of β-O-4 were noticeable cleaved, but the condensed structures in the lignin formed when undergoing autohydrolysis of high severity, resulting in elevated amounts of C-C linkages. Moreover, it was found that autohydrolysis promoted the removal of -OCH3 groups and increased the thermal stability of lignin fractions.

Dodecenylsuccinic anhydride derivatives of gum karaya (Sterculia urens): preparation, characterization, and their antibacterial properties.

Esterifications of the tree-based gum, gum karaya (GK), using dodecenylsuccinic anhydride (DDSA) were carried out in aqueous solutions. GK was deacetylated using alkali treatment to obtain deacetylated gum karaya (DGK). The DGK and its DDSA derivative were characterized using gel permeation chromatography/multiangle laser light scattering (GPC/MALLS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), proton nuclear magnetic resonance spectroscopy ((1)H NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) analysis, and rheological studies. The degree of substitution was found to be 10.25% for DGK using (1)H NMR spectroscopy. The critical aggregation concentration of DDSA-DGK was determined using dye solubilization and surface tension methods. The antibacterial activity of the DDSA-DGK derivative was then investigated against Gram-negative Escherichia coli and Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus. The DDSA-DGK derivative has the potential for use as a stabilizing agent in food and nonfood applications. It can also be developed as an antibacterial agent.

Well-defined poly(DL-lactide)-b-poly(N-vinylcaprolactam) copolymers: synthesis, solution properties and in vitro degradation

Well-defined thermoresponsive amphiphilic poly(DL-lactide)-b-poly(N- vinylcaprolactam) (PDLLA-b-PNVCL) block copolymers with various block compositions were synthesized via a combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). Their structures were confirmed by proton nuclear magnetic resonance spectroscopy (1H NMR) and gel permeation chromatography/multi-angle laser light scattering (GPC/MALLS) measurements. They exhibited reversible temperature-dependent aggregation behavior in aqueous media as characterized by turbidity and dynamic light scattering (DLS) measurements. Their lower critical solution temperatures (LCSTs) increased with the increase in the chain length of PNVCL block and the decrease of the copolymer solution concentrations. These amphiphilic block copolymers self-assembled into aggregates of various morphologies in their aqueous solution, depending on the compositions of the copolymers. As the PNVCL content in block copolymer increased, the morphology of the aggregates changed from spheres to large compound vesicles (LCVs)-like, to irregularly spherical micelles. The viscosity measurement and 1HNMR analyses proved that these copolymers were hydrolytically degradable and the degradation process was accelerated under basic and acidic environments, especially in acidic media.

Emulsification Properties and Molecular Weight Distribution of Combretum Glutinosum Gum

The determination of weight average molecular weight (Mw) and radius of gyration (Rg) of Habeil gum was performed on a gel permeation chromatography-multi angle laser light scattering (GPC-MALLS) system. The results showed three main components of Combretum glutinosum gum designated arabinogalactan protein (AGP), arabinogalactan (AG) and glycoprotein (GP). The Mw of the freeze dried soluble part, freeze dried deacetylated gum, and freeze dried calcium-free gum were 2.06×106, 8.03×105, and 1.40×106 g /mol, respectively. The Mw of hydrophilic and hydrophobic components collected from soluble part gum are 3.16×106 and 6.08×105 g /mol, respectively, while the Mw of hydrophilic and hydrophobic components collected from deacetylated gum are 1.39×106 and 8.36×105 g /mol, respectively. Emulsification studies of the gum fractions showed lowest degree of span value than the starting material indicating good uniformity and increasing in adsorption of protein on oil droplet surface. The results of emulsion studies indicated that a blend of 50% w/w deacetylated Combretum glutinosum gum and 50% w/w Acacia Senegal produced better emulsification properties than the pure mother gum.

Complexation of Bovine Serum Albumin and Sugar Beet Pectin: Structural Transitions and Phase Diagram

The complexation between bovine serum albumin (BSA) and sugar beet pectin (SBP) was studied in situ by coupling glucono-δ-lactone (GDL) induced acidification with dynamic light scattering and turbidity measurements. Individual measurements at specific pHs and mixing ratios were also carried out using zeta potentiometry, gel permeation chromatography-multiangle laser light scattering (GPC-MALLS), and isothermal titration calorimetry (ITC). These investigations together enabled the establishment of a phase diagram of BSA/SBP and the identification of the molecular events during protein/polysaccharide complexation in relation to the phase diagram, which showed five regions: (I) a stable region of mixed individual soluble polymers, (II) a stable region of intramolecular soluble complexes, (III) a quasi-stable region of intermolecular soluble complexes, (IV) an unstable region of intermolecular insoluble complexes, and (V) a second stable region of mixed individual soluble polymers, on lowering pH. We found for the first time that the complexation could take place well above the critical pH(c), the value that most previous studies had regarded as the onset occurrence of complexation. A model of structural transitions between the regions was proposed. The borderline between region II and region III represents the BSA/SBP stoichiometry for intramolecular soluble complex at a specific pH, while that between region III and region IV identifies the composition of the intermolecular insoluble complex. Also studied was the effect of NaCl and CaCl(2) on the phase diagram and structural transitions.

Preparation of low-molecular-weight chitosan derivative zinc complexes and their effect on the growth of liver cancer cells in vitro

Abstract Low-molecular-weight (LMW) chitosan salicylaldehyde Schiff-base and its zinc(II) complexes were synthesized and characterized by Fourier transform-infrared (FT-IR) spectra, transmission electron microscopy (TEM), dynamic light scattering (DLS), gel permeation chromatography-multiangle laser light scattering (GPC-MALLS), and elemental analysis. The results of electrophoretic analysis suggest that the Zn complexes bound to DNA by means of electrostatic interactions and intercalation. The effect of the Zn complexes on the growth of SMMC-7721 liver cancer cells was investigated by sulforhodamine B assay in vitro. The results reveal that the growth of liver cancer cells was inhibited by LMW-chitosan and their Zn complexes. The inhibition rate of the Zn complexes was higher than that of LMW-chitosan ligand. The LMW-chitosan Schiff-base Zn complex exhibited higher anticancer activity than the LMW-chitosan Zn complex. Combining LMW-chitosan with Schiff-base and Zn improved its anticancer activity, which we ascribe to the synergistic effect between the chitosan matrix and the planar construction of the Zn complexes.

Programmed Thermodynamic Formation and Structure Analysis of Star-like Nanogels with Core Cross-linked by Thermally Exchangeable Dynamic Covalent Bonds

Programmed thermodynamic formation of star-like nanogels from designed diblock copolymers with thermally exchangeable dynamic covalent bonds in their side chains and structure analysis of the nanogels were performed. Linear diblock copolymers that consist of poly(methyl methacrylate) block and random copolymer block of methyl methacrylate (MMA) and methacrylic esters with alkoxyamine moiety were prepared by atom transfer radical polymerization (ATRP). By heating the diblock copolymers in anisole, a cross-linking reaction occurred as a result of the radical crossover reaction of alkoxyamine moieties to afford star-like nanogels. Kinetic studies have revealed that the cross-linking behavior reaches equilibrium at a given reaction time, with characteristic reaction behaviors for thermodynamic reactions being observed. The equilibrium structures of the star-like nanogels were controlled by the initial concentrations of diblock copolymers as well as their compositions and molecular weights. Furthermore, by heating the star-like nanogels with excess alkoxyamine, linear polymers were successfully regenerated. The molecular weights and sizes of the nanogels were evaluated by gel permeation chromatography-multiangle laser light scattering (GPC-MALLS) and small-angle X-ray scattering (SAXS) measurements, respectively, and the morphologies of the nanogels were directly observed by scanning force microscopy (SFM).

Synthesis of low polydispersity polybutadiene and polyethylene stars by convergent living anionic polymerization

AbstractStar‐shaped polybutadiene stars were synthesized by a convergent coupling of polybutadienyllithium with 4‐(chlorodimethylsilyl)styrene (CDMSS). CDMSS was added slowly and continuously to the living anionic chains until a stoichiometric equivalent was reached. Gel permeation chromatography‐multi‐angle laser light scattering (GPC‐MALLS) was used to determine the molecular weights and molecular weight distribution of the polybutadiene polymers. The number of arms incorporated into the star depended on the molecular weight of the initial chains and the rate of addition of the CDMSS. Low molecular weight polybutadiene arms (Mn = 640 g/mol) resulted in polybutadiene star polymers with an average of 12.6 arms, while higher molecular weight polybutadiene arms (Mn = 16,000 g/mol) resulted in polybutadiene star polymers with an average of 5.3 arms. The polybutadiene star polymers exhibited high 1,4‐polybutadiene microstructure (88.3–93.1%), and narrow molecular weight distributions (Mw/Mn = 1.11–1.20). Polybutadiene stars were subsequently hydrogenated by two methods, heterogeneous catalysis (catalytic hydrogenation using Pd/CaCO3) or reaction with p‐toluenesulfonhydrazide (TSH), to transform the polybutadiene stars into polyethylene stars. The hydrogenation of the polybutadiene stars was found to be close to quantitative by 1H NMR and FTIR spectroscopy. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 828–836, 2006

Polimery gwiazdziste z rozgalezionymi rdzeniami poli[p-(halogenometylo)styrenowymi

Methods of preparation of core/shell type star-shaped polymers have been presented. The core was either poly[p-(chloromethyl)styrene] [poliPCMS, Formula (I)] or poly[p-(iodomethyl)styrene] [poliPJMS, Formula (II)]. PoliPCMS was synthesized by atom transfer radical polymerization (ATRP) while poliPJMS has been obtained first time via radical polymerization with degenerative chain transfer (Scheme A). PoliPCMS has been used as a core to obtain amphiphilic star-shaped polymers with arms made of poly(ethylene oxide) (PEOX) of different molar mass [equation (2)], in a Williamson reaction by the arm-first method. PoliPJMS core has been used as a precursor in core-first method to obtain well defined star-shaped polymers with the arms made of poly(t-butyl acrylate) (PAKTB), polystyrene [PS, equation (4)] or copolymers PS-block-PAKTB [equation (5)] using the iodine mediated degenerative chain transfer polymerization. Star-shaped polymers have been characterized using gel permeation chromatography/multi-angle laser light scattering (GPC-MALLS) (Fig. 1 and 2, Tables 1-3) and 1 H NMR and 1 3 C NMR spectroscopy.